Poly(arylene sulfide), e.g. poly(phenylene sulfide) (PPS), compositions comprising fillers, reinforcing agents, pigments, processing aids, stabilizers, etc. are known in the art to provide coatings or articles by various molding techniques which have outstanding heat and chemical resistance.
For various reasons it is often desired that a black pigmented PPS article be produced. Carbon black is a well known black pigmenting material which has found widespread use with a variety of polymers including PPS. It is noted here that electrically conductive PPS compositions having 4-50, preferably 4-10% by weight of finely divided carbon black are disclosed in U.S. Pat. No. 3,521,214. For this application a furnace black is specifically preferred. Other patents such as U.S. Pat. Nos. 3,354,129 and 4,115,283 suggest carbon black as a filler with the latter proposing a filler level of 10-20 weight %.
Although furnace black is relatively inexpensive and only low levels, e.g. 1-2 wt. %, are used as pigments in PPS compositions it has been found that the physical (mechanical) properties of the PPS compounds comprising said furnace carbon blacks are significantly lowered compared to compounds containing no pigment. Specifically, tensile strength and flexural strength properties appear to be especially sensitive to the presence of furnace carbon black at pigmenting levels. It is therefore desirable that an inexpensive black pigment be found for use in PPS compounds which does not cause the significant decrease in mechanical properties shown by furnace carbon blacks.
Accordingly, an object of this invention is to provide arylene sulfide polymer compositions containing black carbonaceous pigments.
Another object of this invention is to provide black pigments for arylene sulfide polymers which do not adversely affect the mechanical properties of the polymer.
It is a further object of this invention to provide a method for incorporating black carbonaceous pigments into arylene sulfide polymer compositions.
Other objects, aspects, as well as the several advantages of the invention, will be apparent to those skilled in the art upon reading the specification and the appended claims.